以新鲜豇豆为原料,采用自然发酵(CK组)、接种商业菌种(CS组)、接种自筛直投式菌剂(DVS组)3种方式发酵豇豆,测定发酵过程中发酵液的总酸、pH值及发酵成熟后豇豆的盐度、亚硝酸盐、氨基酸态氮、游离氨基酸、乳酸菌数、色差、感官品质、质构特性,分析发酵方式对酸豇豆品质的影响.结果表明,在发酵过程中,DVS组的总酸增长速度最快,在1~6 d均高于CS组、CK组;CS组、DVS组的pH值下降速率比CK组快,在7 d时CS组pH值最低,DVS组仅次于CS组;在发酵至第7天时,DVS组菌落总数分别比CK组、CS组高33.86%、42.31%.发酵成熟后,DVS组的盐度、亚硝酸盐、b*值最低,氨基酸态氮、游离氨基酸、乳酸菌数、感官评分、硬度、粘力、胶着性、咀嚼性最高,L*值、a*值、弹性与其他发酵方式无显著性差异(P>0.05).综合可知,DVS组不仅发酵启动快,且酸豇豆成品的综合品质更优.
Fresh cowpeas(Vigna unguiculata(Linn.)Walp.)were fermented by three ways:spontaneous fermentation(CK group),inoculation of com-mercial strains(CS group),inoculation of self-screening direct vat set starter(DVS group).The total acidity,pH of the broth total during fermentation and salinity,nitrite,amino acid nitrogen,free amino acids,lactic acid bacteria count,color difference,sensory quality and textural characteristics of finished fermented cowpeas were determined,to analysis the effect of the fermentation methods on the quality of sour cowpeas.The results showed that during fermentation,the total acidity of DVS group increased faster than those in both CK and CS group from 1-6 d.The pH of CS and DVS group decreased faster than CK group and the CS group reached the lowest on 7 d,followed by DVS group.The total bacteria count in DVS group was 33.86%and 42.31%higher than that in CK and CS group respectively on 7 d.After fermentation,the DVS group had the lowest salinity,nitrite,b*values,and the highest amino acid nitrogen,free amino acids,lactic acid bacteria count,sensory score,hardness,viscosity,gelatinousness and chewi-ness,but L*values,a*values and elasticity were not significantly different from the other fermentation methods(P>0.05).By comprehensive anal-ysis,the DVS group not only had faster fermentation initiation and higher acid tolerance,but the finished product also had better overall quality.